demotool/bloom-combine.glsl

#version 450 core

layout( location = 0 ) uniform sampler2D u_MainInput;
layout( location = 1 ) uniform sampler2D u_BlurInput;
layout( location = 2 ) uniform vec2 u_OutputSize;

layout( location = 0 ) out vec3 color;

void main( void )
{
	vec2 tmp = gl_FragCoord.xy / u_OutputSize;
	float f = .7;
	color = textureLod( u_MainInput , tmp , 0 ).rgb;
	for ( int i = 0 ; i < 5 ; i ++ ) {
		color += f * textureLod( u_BlurInput , tmp , i ).rgb;
		f *= .7;
	}
	color = color / ( color + 1. );
	color = pow( color , vec3( 2.2 ) );
}